Apparatus and method of coating molds with carbon



H. S. LEE

July 1927.

APPARATUS AND METHOD OF COATING MQLDS WITH CARBON Filed F sh. 16. 1925 2Sheets-Sheet, 1

R m m m ATTORNEY.

1,6 July 12,1927. HSLEE 35 370 APPARATUS AND METHOD OF COATING MOLDSWI'I H CARBON Filed Feb. 16, 1925 2 Sheets-Sheet 2 Patented July 12,1927.

UNITED STATES,

8. LEE, OF PLYMOUTH, MICHIGAN.

APPARATUS AND EETHOD OF COATING HOLDS WITH CARBON.

Application filed February matrix of the mold.

I The present method of coating molds with carbon is the passing ofa'mold past a ball of incomplete combustion flame, the carbon bein 'deosited on the mold. This works fair y we ,but it is foundthat quiteoften.

the carbon is deposited unevenly and results in certain portions of themold having a thicker coating of carbon than the remaining portion ofthe mold. This results in an uneven castiapg, as the thicker portions ofcarbon make pressions in the casting and quite often these diflicultiesnecessitate the junking of the casting. -With my process the carbon isevenly distributed and there is nopossible chance of an uneven coatingofcarbon being deposited. on the mold and thereby it reduces the number ofcastings which are wasted.

One of the objects of my improved method is the moving of a flame alongthe surface of the mold at a uniform rate of speed and -maintaining theflame at a constant distance from the surface of the matrix of the mold,

which is to be coated with the carbon.- Another object is theassociation of my method for permanent mold machines wherein a plurality.of molds are continually moving along a certain line. My method may beeasily adapted to such a machine by moving the flame in conjunction withthe -m0ving molds.

This method may be applied to various types of molding machines whereinthe molds are moved or conveyed in a straight line or are located on arevolving table such as described in pending application 'erial N 0.4,744.

, In the drawings:

Fig. 1 is a Iplan view of a portion of a permanent mo d machine, showingone form of mechanism for performing my method.

Fig. 2 is a section on the line 2-2 of Fig. 1, which shows one form ofapparatus for passing the flame along the surface of V -the' matrix ofthe mold.

.F Fig. -3 is a section on the line 33 of arried on conveyer chains orbel s a are the supports 6. These supports carry the guide rods 0, whichsupport t e mold carriers 16, 1-925. Serialdflo. 9,528.

d and e, the carrier (5 being held stationary near the extremity of theguide rods and the inner carrier e being slidably guided on the guidenods. These mold carriers each carry the mold halves f which areprovided with a mold cavity or matrix g, thesurface of which it isdesired to coat! with an even coating of carbon, which serves toinsulate the mold from the molten metal and also serves as a partingmaterial permitting the automatic discharge of the casting when the samehardens. The inner movable mold carrier 0 isprovided with the inwardlyextending tongue 71., which carries the roller 71 on its inner end. Thisroller '5 is adapted to' be engaged in the cam groove 7' so that as themolds are moved longitudinally the roller rides in the'cam groove,thereby moving the mold carrier e to separate or close the molds.

Supported on the super-structure k,which is composed of any suitablydesigned steel framework, is a'triangular track m,which has one side 1:.inclined at an angle to the horizontal. Guided in these tracks is aflame apparatus 0, which is provided with the rollers 12 engaging in thetracks. This flameapparatus supports the horizontal gas pipe r, and thedepending T-shaped gas distributing pipe, 8 provided with, the burnertips t, for proecting the flame laterally against the sur ace of themold in a fanshaped flame. Carried by the gas pipe 7' is a dependingtrip arm u, which is engaged by the trip v carried on the movablesupports 6. As the molds are moved along, the

trip '0 engages the arma and moves the flame carrying apparatus to theright, as viewed in Fig. 2, thereby causing the rollers p to ride up theinclined track 11., thereby raising the burner tips it into the dottedline position, as shown in Fig.2.

The upper end of the inclined track 11. is

closed by a trap door w, which allows the rollers to pass by. Now whenthe rollers reach t 's upper sition, carrying the flame carrier with it,t e arm a is raised and permits the trip u topass under, thereby-releasingthe arm and allowing the coil tension spring as, which issecured to a portion of the supperstructure and to the flame apparatus,to return the flame apparatus along the horizontal track y, therebyholding the flame or burner tip in its upper level until the samereturns to approximately its original position over the following pairof molds, whereupon the same is, allowed to drop downthe vertical track1 and to drop the flame in the following set of molds, whereupon theflame apparatus is again moved for repeating the operation for coatinthe following set of molds.-

he burner tips are flattened out so as to provide a fan-shaped flame,which is di' rected against the matrix ofthe mold and coats a portion ofthe matrix with a coat of carbon. This flame is moved by the mechanismabove described, and is raised slowly but at a uniform speed, therebymoving the flame along the surface of the matrix of the mold at auniform and constant speed. This exposes. the surface of the matrix ofthe mold to a flame of equal intensity for a constant length of time,and as a result a uniform coatin of carbon is deposited thereon andavoids t e possibilty of some of the surface having a thicker coating ofcarbon than the remaining portion.

Obviously this fan-shaped flame could be varied within certain limits asa fan-shaped flame such as shown in this apparatus is 'more'particularlyadapted for coating a mold provided with a circular form of matrix.

' for shooting Where flat surfaces are desired to becoated with carbon,several 'etscould be utilized a thin s eet of flame against the surface,the width of the flame depending upon the amount of surface to becoated. The essential feature is the moving of a sheet of flame .alongthe surface of the matrix of a mold-in a direction at right angles tothe plane of the flame, thereby exposing all portions of the surface ofthe matrix to the flame for the'same length of time, and to expose allparts of the surface to a flame of equal intensity.

VVha t I claim is:

1. The method. of de of carbon overthe sur ositing an even coat ace ofthe matrix of a mold, which comprises the moving of a single incompletecombustion sheet flame aeeaeee having a greater relative width thandepth at a uniform speed along the entire surface of the matrix of saidmold in a direction which is at right angles to the plane of said sheetflame, and parallel to the sur face to be coated. I

2. The method of depositing an even coatof carbon over the surface .ofthe matrix of a mold, which comprises the moving at a constant speed bysaid mold of a single incomplete combustion relatively thin sheet flamehaving a uniform heat intensity along the entire surface of the matrixof said mold and moving in a direction which is at right angles to theplane of said sheet flame and parallel to the surface toibe coated.

3. In an apparatus for coating .molds with carbon, the combination of aburner provided with means for projecting a sheet.

flame, and means for 'moving'said burner "along {the surface; of saidmold at right angles to the plane of the sheet,flame.

4. In an apparatus for coating molds with carbon, the combination of aburner pro vided with a burner tip having a-jet opening which isrelatively long and narrow for the purpose of projecting a sheet flame,and means for moving said burner along the surface of said mold at rightangles to the plane of the sheet flame.

5. In an apparatus for coating molds with carbon, the combination of aburner pro vided with means for projecting a" fan.- shaped sheet flame,said means located at a point substantially equi-distant from all pointsin the mold surface in the plane of the flame, and means for moving saidburner parallel to the surface of the mold and at right angles to theplane of the fanshaped sheet flame.

In testimony whereof'I have aflix'ed my signature.

- HARRY s. LEE;

